Racial superiority was a key motivation behind European imperialism as they through some scientific discoveries and using Darwin theory they were trying to justify that they are superior because of their genetics and white skin color.
Secondly, The economic boom they gained by the industrial revolution led them to find new places for the exploitation of land and resources.
Further, there was a rivalry among European Nations for the colonies. it became a matter of prestige for them.
The stamp tax was an increase in taxes on commodities for the colonies in North America. These increases gave no added benefit in return, like representation in government.
